In a forest grove not far from the nation's capital, several dozen men and women gather. As the light fades, they enact a ritual over a century old but as fresh and searing as the flame they ignite.

A cross, on fire.

They call themselves "the invisible empire" for a reason: They thrive in secrecy, almost never permitting outsiders in.

Who are they?

"You don't know who I am," one man said. "You could think the world of me, and yet if you see me in this hood and knew who I was, your whole thoughts could change."

"I've been a fireman, I've been in the Navy," said another.

The people wearing these robes walk among us. Yet together, as they were this summer in Martinsville, Va., they are the Ku Klux Klan.

"Klansmen, the fiery cross!" a man shouted.

"For God ... For country ... For race! ... And Klan!" the call and response went.

And just a couple of weeks ago, in Tupelo, Miss., a similar scene transpired.

"Klansmen, we are the only klan in the state of Mississippi!" a man shouted.

"White power!" yelled another.

Over the past four months, "Nightline" has been granted rare access to the Klan -- its rituals, its members, its message of racial segregation, which it spreads with a new urgency.

"We have to protect ourselves, or they will kill us!" Steven Howard, a Klan group leader in Mississippi, said.

To get to the heart of it, we headed south to meet Howard. Along the way, we passed through areas scarred by the battles -- the lynchings and church bombings -- of the civil rights era, making a stop at The Southern Poverty Law Center, which is in Montgomery, Ala. Senior Fellow Mark Potok and his SPLC colleagues have been fighting the KKK in courtrooms and classrooms for decades.

Potok agreed with some Klan members' view that President Obama had been the Klan's most effective recruiting tool in the past four or five years.

"I think there's some truth to that," Potok told "Nightline" co-anchor Cynthia McFadden. "Immediately after Obama was elected, we saw two of the largest hate websites in the country crash."

Potok said they had seen the Klan rise, fall and rise again. By the late 1980s, it had dwindled to a few hundred. But now, the story is very different.

"The Klan and other [similar] groups grew pretty significantly by our account," Potok said. "Six hundred groups in the year 2000 to 1,018 last year."

"And that's not the half of it," he continued. "Militia groups have come back, and have come back with a force that is amazing."

We followed the aforementioned Klan group leader, Steven Howard, 31, to a remote spot with a trailer next to the woods. Cell phone service was spotty. Howard's wife, Nicole, was cooking and serving food, creating an atmosphere reminiscent of a regular Saturday-night barbecue. The Howards' 11-year-old daughter was there.

"You cannot get any better southern dish than what you get here!" Howard said.

When the interview began, the regular feeling ended.

"Black people and white people are nowhere related," Howard said. "In my opinion, black people evolved from animals. That's what I think they evolved from: apes."

Howard Says He Would 'Disown' Daughter If She Brought Home Black Boyfriend

Later, Klanspeople gather in the remote location for what they call a "cross lighting." It is legal in the woods, on private property. It is punishable with 10 years in federal prison if done on a black resident's lawn.

Torches were wrapped, the cross prepared. The air reeked of kerosene.

"This is what we call the Klan cologne," Howard said.

Howard explained the ritual that would unfold when evening came.

"Through lighting the cross we signify that the cross is the light of the world, and we purify our race and we purify our people. ... We're lighting crosses to let people know that America is in turmoil right now, and there is people here to protect the Ku Klux Klan, and that's what we're here to do."

His fellow Klansman, who asked not to have his face shown on camera for fear he'd be fired from his job, resumed preparations for the evening's rituals.

"That's just the outlook that they want to give you," the man answered. "That ain't truth; not everybody was like that."

Did he think he was being a good Christian?

"Yeah, this is state of Christianity. This is our Christianity ... plain and simple."

His wife would become "naturalized" into the Klan tonight, a membership rite rarely seen by outsiders.

Howard said he let us in to show us that the new Klan is neither racist nor violent.

"I'm not saying that I don't like black people," he said, "I'm saying that I believe in racial segregation. I believe that we need to be separated. ... Let them set up their own state, where they belong, and give them their own homeland."

"You can't trust a black person as far as you can throw them," he said. "I believe that 100 percent."

"If your daughter, once she got older, came home and said, 'I want to go out with a black boy?'" McFadden asked.

Howard laughed and said, "I'm not going to say what I'd like to say on camera. But, I'd disown her. I'd disown her. I wouldn't have nothing else to do with her for the rest of my life."

"She wants to be like her Daddy," Howard said. "You can't blame any child for wanting to be like their father. Any child would be. I wanted to be like my father. He was a Vietnam veteran. I love my dad. I always looked up to my dad, even though he's not always been there for me."

Did Howard consider himself a racist?

"I consider myself a white separatist. A bigot? No. A racist? That's fair; you could call me a racist. Because a racist is just somebody who is racially aware, that thinks about race."

Some might argue that media coverage of the Klan helps them and their ideas. Mark Potok has heard the argument many times.

"Every time that you have a story on the front page of the local newspaper about a Klan rally ... the Klan or particular group does get a [new] member or two," he said. "On the other hand, I think that the reality is, 99.9 percent of people who read about that or hear on television or radio about these groups are essentially inoculated against them. It can absolutely harm [the groups] more than it's helping them."

While violence was the calling card of the old Klan, Howard repeatedly said the Klan had moved on from that tactic. Yet he and others freely talked about a looming race war if Obama was re-elected. The KKK and other groups call it "the storm."

"Oh, it's going to happen. And I fear it. ... And it ain't just me. ... If he gets four more years, Barack Obama will ruin this country. And white people will be in concentration camps, and if you don't think that white people [can] be in concentration camps, [you] are sadly mistaken."

His solution to avoid this is an all-white south. All blacks, Hispanics and Jews would be banned and given someplace else in America to live.

When pressed, Howard admitted his idea threatened his stated commitment to nonviolence.

"If they will not peacefully then the only way is through violence," he said.

"A race war," McFadden said.

"Very much so," Howard said.

Another Klan leader in Mississippi was Sam Bowers, the man responsible for the murders dramatized in "Mississippi Burning."

When he saw the movie as a boy, Howard said, he asked his mother, "Who are these guys on here that's got these hoods on their heads and beating up these people and stuff like that? And my mom said, 'Baby, that's the Klan.' And that's when I was 7, 8 years old. And that's when I first knew what the Klan was, and after that I fell in love with it."

"I don't endorse murder," Howard said.

What about other forms of violence?

"I just don't endorse murder."

So he was OK with other forms of violence?

"You're gonna have to form your own opinion on that," he said.

Although there are more Klan members now than in past decades, the numbers are still not more than several thousand, according to the SPLC. But the danger they pose isn't collective but individual.

"It gets dangerous not so much because a whole bunch of Klansmen get together and plan to blow up a federal building or to murder 1,000 people with a bomb," Potok said. "It's sort of these lone wolf characters that get frustrated with their leaders, that break away, that one day walk out of their house and start shooting. We see a lot of signs of that kind of anger building, and ultimately it will translate into criminal violence."

Howard carries a pistol, concealed, at all times, he said.

Howard admitted he was angry at the government.

"I'm very mad at the government. ... It hurts my heart to see all the people that I lost and I won't ever get them back. ... So yeah, do I got a lot of hate in me? You better -- yeah, I got a lot of hate in me. A lot of hate for nothing. I got a lot of built up in me, a lot of hurt. A lot of hurt because I don't understand it."